Apparatus, system and method for debris removal

ABSTRACT

An apparatus, method and system for debris removal using a debris removal tool. The tool has a generally-cylindrical tool body having an upper end, a lower end, a central axis, an interior chamber and an external surface. A nozzle plate, disposed within the tool body, has an array of nozzles disposed therein. Each of the nozzles has a principal axis angled with respect to the central axis of the body of the debris removal tool, in order to direct fluid from the interior chamber of the tool body to the exterior of the tool at an angle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional application Ser. No. 62/548,753, filed on Aug. 22, 2017.

TECHNICAL FIELD OF THE DISCLOSURE

The present disclosure relates to an apparatus, system and method designed to remove sand, scale or other debris from the well bore of an oil or gas well where conventional sand and debris removal methods and systems are not effective.

BACKGROUND

During the process of drilling an oil or gas well, substantial quantities of sand, scale and other debris are produced by the drilling process. This debris must be continually removed from the well bore in order for the drilling process to proceed effectively. If the debris is not removed in an effective and efficient manner, the drilling process may be delayed and possibly halted.

SUMMARY OF THE DISCLOSURE

According to a first aspect, the present disclosure is directed to a debris removal tool having a generally-cylindrical tool body having an upper end, a lower end, a central axis, an interior chamber and an external surface. A nozzle plate, disposed within the tool body, has an array of nozzles disposed therein. Each of the nozzles has a principal axis angled with respect to the central axis of the body of the debris removal tool, in order to direct fluid from the interior chamber of the tool body to the exterior of the tool at an angle. An array of radially-spaced, angled apertures is formed in the tool body, connecting the interior chamber of the tool body to the external surface thereof. Each of the angled apertures has a principal axis aligned to the principal axis of a nozzle in the nozzle plate.

In certain embodiments, the nozzle plate holds at least 2 nozzles. In others, the nozzle plate holds at least 4 nozzles. According to some embodiments, the nozzles are oriented at approximately 12 degrees from the center line of the body. In certain embodiments, the debris removal tool has threaded connections at the upper and lower ends of the body. Depending on the specific application, a debris screen may be disposed in the lower end of the tool body. In certain embodiments, a tube type screen may be disposed in the upper end of the tool body. According to certain configurations, the nozzle plate may incorporate o-rings on the outside diameter thereof to promote sealing. The nozzle plate may have a notched slot to ensure proper alignment of the nozzles with the angled apertures.

According to a second aspect, the present disclosure is directed to a method of removing debris from a wellbore. The method includes the steps of securing a debris removal tool to a work string, disposing the work string in the wellbore and pumping fluid down the tubing of the work string and through the debris removal tool. The debris removal tool has a generally-cylindrical tool body having an upper end, a lower end, a central axis, an interior chamber and an external surface. A nozzle plate, disposed within the tool body, has an array of nozzles disposed therein. Each of the nozzles has a principal axis angled with respect to the central axis of the body of the debris removal tool, in order to direct fluid from the interior chamber of the tool body to the exterior of the tool at an angle. An array of radially-spaced, angled apertures is formed in the tool body, connecting the interior chamber of the tool body to the external surface thereof. Each of the angled apertures has a principal axis aligned to the principal axis of a nozzle in the nozzle plate.

According to a third aspect, the present disclosure is directed to a system for removing debris from a wellbore. The system includes a work string, comprising tubing, disposed in a wellbore, a debris removal tool, secured to the work string and a pump in fluid communication with the work string, operable to pump fluid down the tubing of the work string and through the debris removal tool. The debris removal tool has a generally-cylindrical tool body having an upper end, a lower end, a central axis, an interior chamber and an external surface. A nozzle plate, disposed within the tool body, has an array of nozzles disposed therein. Each of the nozzles has a principal axis angled with respect to the central axis of the body of the debris removal tool, in order to direct fluid from the interior chamber of the tool body to the exterior of the tool at an angle. An array of radially-spaced, angled apertures is formed in the tool body, connecting the interior chamber of the tool body to the external surface thereof. Each of the angled apertures has a principal axis aligned to the principal axis of a nozzle in the nozzle plate.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the features and advantages of the present disclosure, reference is now made to the detailed description along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:

FIG. 1 is a three-dimensional view of a multiple-jet debris removal tool according to one embodiment of the present disclosure;

FIG. 2 shows a lower three-quarters view of a downhole tool suitable for use with the present disclosure;

FIG. 3 is a side view of the downhole tool depicted in FIG. 2;

FIG. 4 is an upper three-quarters view of a downhole tool of FIGS. 2 and 3;

FIG. 5 is an internal view of the downhole tool depicted in FIGS. 2-4;

FIG. 6 shows the downhole tool of FIGS. 2-5 being lowered into a well at the end of a drilling string;

FIG. 7 shows the drilling string of FIG. 6 being attached to another section of drilling string;

FIG. 8 is a side cutaway view of a bottom sub designed for use with the present disclosure;

FIG. 9 is a side cutaway view of a multiple jet debris removal tool according to one embodiment;

FIG. 10 is a side cutaway view of a top sub designed for use with the present disclosure;

FIG. 11 is a side section view of the multiple jet debris removal tool of FIG. 9;

FIG. 12 is a side view of the nozzle plate sleeve of the multiple jet removal tool;

FIG. 13 is a side cutaway view of the main body of the debris removal tool of the present disclosure;

FIG. 14 is a side view of a bottom stabilizer suitable for use with the present disclosure;

FIG. 15 is a side view of a top stabilizer suitable for use with the present disclosure; and

FIG. 16 is a flowchart showing the steps of a method for removing debris using the disclosed debris removal tool.

DETAILED DESCRIPTION OF THE DISCLOSURE

While the making and using of various embodiments of the present disclosure are discussed in detail below, it should be appreciated that the present disclosure provides many applicable inventive concepts, which can be embodied in a wide variety of specific contexts without departing from the spirit and scope of the disclosure. The specific embodiments discussed herein are merely illustrative and do not delimit the scope of the present disclosure to these specific embodiments disclosed.

In the following description, reference may be made to certain spatial or geometric relationships between various components and to the orientation of various features of components as the devices are depicted in the attached drawings. As will be recognized by those skilled in the art after a complete reading of the present disclosure, the devices described herein may be positioned in a variety of orientations. Thus, the use of terms such as “down,” “up,” “above,” “below,” “upper,” “lower” or other like terms to describe spatial relationships between various components or to describe the spatial orientation of features of such components should be understood to describe a relative, rather than an absolute, relationship between the components.

In the interest of clarity, not all operational details of an actual implementation will be included in the present disclosure, but will be known to those of skill in the art. In the course of development of any working embodiment, numerous implementation-specific decisions will be made to achieve specific goals, which will vary from one implementation to another.

Turning now to FIG. 1, this figure shows a three-dimensional side view of a multiple-jet debris removal tool 100 according to one embodiment of the present disclosure. Tool 100 comprises a cylindrical body 102 having an upper end 104 and a lower end 106. An array of radially-spaced, angled apertures 108 are formed in the body 102. During operation, a jet of fluid 110 is ejected from each aperture 108, in order to clear out debris from the well bore.

The debris removal tool of the present disclosure may be manufactured from a variety of materials. According to one embodiment, the tool may be manufactured from 4140 quenched, tempered and stress relieved steel having all the strength properties of P-110 material. The required tensile strength may vary by application. In certain embodiments, a tensile strength between 400,000 and 550,000 is sufficient.

The dimensions of the components may vary, but the outer body will generally be of sufficient length to accommodate top and bottom connections, an inner nozzle plate and exhaust holes angling outward into the annulus at the appropriate angle. According to one embodiment, the nozzles are oriented at 12 degrees from the center line of the tool.

The diameter of the tool will vary according to the size of the well casing within which it is used. In certain embodiments, a tool of 3.5″ outside diameter may be suitable for 5.5″ and larger casing. A tool of 3.125″ may be more suitable for casing between 4.5″ and 5″. The threaded connections at the ends of the tool may vary by application. Certain embodiments use a modified acme thread having a pitch of 6.

While pumping down the work string, the overall flow rate is divided among the nozzles. With four nozzles, at a total flow rate of 52.5 to 63 gallons per minute, the flow rate per nozzle will be between 13.2 and 15.75 gallons per minute. This flow rate will generate sufficient velocity through the nozzle jets to move the water from the inside of the mixing chamber into the annulus.

As a general matter, there must be sufficient head pressure above the tool to facilitate effective debris removal. For certain embodiments, it is recommended to provide at least 250′ of fluid in the well bore above the tool to provide sufficient head pressure. Assuming 250′ head pressure of fresh water, this will create a minimum of 108 psi. The fluid in the wellbore annulus will move around the bottom of the work string instantly replacing the fluid that has been jettisoned out of the mixing chamber, thereby establishing a reverse circulation pattern from the tool to the bottom of the work string, up through the floats and cavity, back up the tool and returned again to the annulus. Excess power fluid will be absorbed into the producing zone.

A higher fluid level in the wellbore results in more head pressure available to move a higher volume of fluid into the cavity. The only known head pressure is calculated from the known original fluid level. The nozzles act as a bottom hole choke point, letting the fluid inside the work string build up to an increased pressure across the jets.

The context within which the debris removal tool and system is used is shown in FIGS. 2-7. FIG. 2 shows a lower three-quarters view of a downhole tool suitable for use with the present disclosure. FIG. 3 is a side view of the downhole tool depicted in FIG. 2. FIG. 4 is an upper three-quarters view of a downhole tool of FIGS. 2 and 3. FIG. 5 is an internal view of the downhole tool depicted in FIGS. 2-4. FIG. 6 shows the downhole tool of FIGS. 2-5 being lowered into a well at the end of a drilling string.

The details and parameters to be employed in a sand or debris removal operation will be determined based on the particular application. Debris to be removed may comprise sand, ESP bands, frac sleeves, scale, junk or a combination of all of above.

FIG. 16 depicts a flowchart 200 showing the key steps in a debris removal operation using the disclosed apparatus and system. After the appropriate tool type has been determined, the appropriate debris removal tool may be attached to the work string (step 202) and run in the hole on the work string to tag fill. A static fluid level will generally be determined at this point. A mill, burning shoe, bit or some other device will be attached to the bottom of the tubing specific to the job at hand (step 204). Flapper type floats will often be used, having a threaded connection specific to tubing work string thread being used.

In certain applications, one joint or (1) 4-6′ pup joint of tubing placed between two flapper type floats may be used to allow space for debris or junk to be spread out between the floats. This will prevent having one float stuck in the open position but not the other float. The use of a sub over a joint is recommended, since if the bottom float is held open for some reason, the operator is only dumping a small amount of debris back into the well bore when TOH vs a full joint.

It is generally desirable to provide a sufficient cavity within the work string tubing to allow sand and debris to be contained above the floats. This is determined by the point at which fill was tagged and where static fluid level was identified in the well bore.

A left hand release safety joint with threaded connections specific to the work string used may be placed in the work string cavity. This allows the tool to be removed if a problem occurs with sticking at the bit or any place below the safety joint. With the tool removed, the work string can be placed back in the hole and the safety joint screwed back together. Normal wireline fishing activities can continue at this point. If deemed necessary, a screen sub may be installed above the safety joint to prevent large pieces of debris from plugging the suction screen on the bottom of the debris removal tool.

The debris removal tool is placed in the string with connections specific to the work string being used for the clean out. Stabilizers of sufficient outside diameter may be installed above and below the tool to prevent wear from continuous rotation on a horizontal plane that would wear down the OD of the tool. This can also improve efficiency by raising the exhaust ports above the casing wall.

The debris removal tool may incorporate a screen in the bottom of the tool to prevent large pieces of debris from returning to the well bore annulus, which may cause problems in removing the work string from the well bore. The debris removal tool may also have a tube type screen in the top of the tool to prevent plugging of the nozzles by foreign debris from a portable water source or scale from inside of work string. Another screen may be placed in the discharge line of a pump that is supplying the power fluid. A screen in the suction between the water source and pump may also be used to prevent debris from getting into the pump. A power swivel may be attached at the surface for means of rotation.

After the apparatus is disposed in the wellbore (step 206), fluid is pumped down the tubing at an appropriate flow rate and pressure (step 208). Normal operations may be pumping on a vacuum since the well may not circulate, but if the wellbore does fill up and begin to circulate, it will not affect the performance of the tool. Horizontal wells with a long length of producing zone open will rarely support a column of fluid. If so, the wellbore is plugged off. When the bridge is removed, or loosened with the debris removal system, the fluid level will fall back to static depth.

FIG. 7 shows the drilling string of FIG. 6 being attached to another section of drilling string. Normal connections or additions of work string tubing continue until a predetermined depth is reached or progress is stopped due to something obstructing the tool of choice on bottom. This could be something in the well bore that the tool of choice cannot mill up, something has plugged the system, or screens becoming blocked by debris, thus stopping flow into the system. The cavity may become filled with sand. The operator needs to be mindful of the amount of sand that is cleaned out during operations. It is not advisable to be returning large amounts of sand into the annulus.

In such an event, the work string is removed from the hole and the cavity is emptied in a safe environmentally friendly process. The bit or tool on the bottom is inspected to look for foreign material or wear. The bottom hole assembly may be changed if necessary to proceed with the task at hand.

The various components of the presently-disclosed sand and debris removal system are shown in FIGS. 8-15. FIG. 8 is a side cutaway view of a bottom sub designed for use with the present disclosure. FIG. 9 is a side cutaway view of a multiple jet debris removal tool according to one embodiment. FIG. 10 is a side cutaway view of a top sub designed for use with the present disclosure. FIG. 11 is a side section view of the multiple jet debris removal tool of FIG. 9.

FIG. 12 is a side view of the nozzle plate and sleeve of the multiple jet removal tool. As seen in FIG. 12, the nozzle plate has multiple nozzles that direct fluid from the centers of the exhaust nozzles. According to one embodiment, the nozzle plate holds four nozzles. Alternate embodiments may use more or fewer than four. In this embodiment, the nozzle plate incorporates o-rings on the outside diameter to seal against power fluid pumped down the tubing entering the mixing chamber. It has a notched slot for proper alignment of the nozzles with the exhaust holes.

FIG. 13 is a side cutaway view of the main body of the debris removal tool of the present disclosure. FIG. 14 is a side view of a bottom stabilizer suitable for use with the present disclosure. FIG. 15 is a side view of a top stabilizer suitable for use with the present disclosure.

While this disclosure has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. The description as set forth is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. The embodiments and examples set forth herein are presented to best explain the present disclosure and its practical application and to thereby enable those skilled in the art to make and utilize the disclosure. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the disclosure will be apparent to persons skilled in the art upon reference to the description. Those skilled in the art will recognize that the foregoing description and examples have been presented for the purpose of illustration and example only. Many modifications and variations are possible in light of the above teachings without departing from the spirit and scope of the following claims. It is, therefore, intended that the appended claims encompass any such modifications or embodiments. 

1. A debris removal tool comprising: a generally-cylindrical tool body having an upper end, a lower end, a central axis, an interior chamber and an external surface; a nozzle plate, disposed within and secured to the tool body, having an array of nozzles disposed therein, having principal axes angled with respect to the central axis of the body of the debris removal tool, in order to direct fluid from the interior chamber of the tool body to the exterior of the tool at an angle; and an array of radially-spaced, angled apertures formed in the tool body, connecting the interior chamber of the tool body to the external surface thereof, each having a principal axis aligned to the principal axis of a nozzle in the nozzle plate.
 2. The debris removal tool as set forth in claim 1 wherein the nozzle plate holds at least 3 nozzles.
 3. The debris removal tool as set forth in claim 1 wherein the nozzle plate holds at least 4 nozzles.
 4. The debris removal tool as set forth in claim 1 wherein the nozzles are oriented at approximately 12 degrees from the center line of the body.
 5. The debris removal tool as set forth in claim 1 further comprising threaded connections at the upper and lower ends of the body.
 6. The debris removal tool as set forth in claim 1 further comprising a debris screen disposed in the lower end of the tool body.
 7. The debris removal tool as set forth in claim 1 further comprising a tube type screen disposed in the upper end of the tool body.
 8. The debris removal tool as set forth in claim 1 wherein the nozzle plate incorporates o-rings on the outside diameter thereof.
 9. The debris removal tool as set forth in claim 1 wherein the nozzle plate has a notched slot for proper alignment of the nozzles with the angled apertures.
 10. A method of removing debris from a wellbore, the method comprising the steps of: securing a debris removal tool to a work string; disposing the work string in the wellbore; and pumping fluid down the tubing of the work string and through the debris removal tool; wherein the debris removal tool comprises: a generally-cylindrical tool body having an upper end, a lower end, a central axis, an interior chamber and an external surface; a nozzle plate, disposed within the tool body, having an array of nozzles disposed therein, having principal axes angled with respect to the central axis of the body of the debris removal tool, in order to direct fluid from the interior chamber of the tool body to the exterior of the tool at an angle; and an array of radially-spaced, angled apertures formed in the tool body, connecting the interior chamber of the tool body to the external surface thereof, each having a principal axis aligned to the principal axis of a nozzle in the nozzle plate.
 11. The method of debris removal as set forth in claim 10 wherein the nozzle plate holds at least 2 nozzles.
 12. The method of debris removal as set forth in claim 10 wherein the nozzle plate holds at least 4 nozzles.
 13. The method of debris removal as set forth in claim 10 wherein the nozzles are oriented at approximately 12 degrees from the center line of the body.
 14. The method of debris removal as set forth in claim 10 wherein the debris removal tool further comprises threaded connections at the upper and lower ends of the body.
 15. The method of debris removal as set forth in claim 10 wherein the debris removal tool further comprises a debris screen disposed in the lower end of the tool body.
 16. The method of debris removal as set forth in claim 10 wherein the debris removal tool further comprises a tube type screen disposed in the upper end of the tool body.
 17. The debris removal tool as set forth in claim 10 wherein the nozzle plate incorporates o-rings on the outside diameter thereof.
 18. The debris removal tool as set forth in claim 10 wherein the nozzle plate has a notched slot for proper alignment of the nozzles with the angled apertures.
 19. A system for removing debris from a wellbore, the system comprising: a work string, comprising tubing, disposed in a wellbore; a debris removal tool, secured to the work string; and a pump in fluid communication with the work string, operable to pump fluid down the tubing of the work string and through the debris removal tool; wherein the debris removal tool comprises: a generally-cylindrical tool body having an upper end, a lower end, a central axis, an interior chamber and an external surface; a nozzle plate, disposed within the tool body, having an array of nozzles disposed therein, having principal axes angled with respect to the central axis of the body of the debris removal tool, in order to direct fluid from the interior chamber of the tool body to the exterior of the tool at an angle; and an array of radially-spaced, angled apertures formed in the tool body, connecting the interior chamber of the tool body to the external surface thereof, each having a principal axis aligned to the principal axis of a nozzle in the nozzle plate. 